SANTA CLARITA, Calif. (AP) – Investigators picked through scorched tire rims, truck axles and other wreckage Sunday hoping to pinpoint what triggered a fiery interstate tunnel pileup that killed three, while police and commuters braced for a traffic nightmare at the start of the work week.

Interstate 5 was shut down in both directions around the crash site, snarling traffic on surrounding roads, where drivers looked for alternative routes after Friday night’s pileup engulfed more than two dozen trucks and other vehicles in flames.

Warren Stanley, California Highway Patrol assistant chief, refused to speculate on the cause of the crash but said authorities would finish their on-scene investigation Sunday. He did not know when findings would be released.

Investigators determined that 28 commercial vehicles – including many big rigs – and one passenger vehicle were involved in the crash, which killed two men and an infant and injured at least 10 people, said John Tripp, Los Angeles County deputy fire chief.

The fire spread from vehicle to vehicle, sent flames shooting nearly 100 feet in the air outside the tunnel and reached temperatures as high as 1,400 degrees, Tripp said.

It was remarkable that 10 people were able to escape on their own, given the extent of the crash and the intensity of the blaze, fueled for hours by truck cargo, the deputy chief said.

“When we look at tunnel fires … it’s pretty miraculous those people were able to get out,” Tripp said.

The fire burned nearly everything it touched, leaving behind only “molten metal, frames of vehicles,” he added.

Gov. Arnold Schwarzenegger declared a state of emergency in Los Angeles County, which will allow the state to deploy emergency workers and equipment and give aid to local government.

The southbound lanes of I-5 were closed for 21/2 miles; the northbound side was closed for about a mile.

Officials hoped to reopen the southbound lanes by Tuesday with detours around the tunnel area, California Department of Transportation district director Doug Failing said. Northbound lanes could reopen 24 hours later.

The acrid smell of burned oil and rubber lingered Sunday at the 550-foot tunnel. The roadbed and walls where charred black, and concrete had fallen away in places, exposing the structure’s steel skeleton.

A front loader shoveled blackened debris into a dump truck. Investigators moved among the wreckage, examining debris and taking notes. Charred vehicle parts were discernible in twisted, blackened masses.

Crews planned to bring in steel supports to add strength to the damaged tunnel. Engineers drill samples out of the tunnel wall to assess the damage, Failing said.

Highway engineers used hammers and other tools while examining the tunnel for safety. The tunnel is a truck bypass that runs beneath eight lanes of I-5, the main West Coast interstate, linking Mexico and Canada.

Commuters who depend on the stretch of freeway 30 miles north of Los Angeles that carries about 225,000 vehicles a day faced the prospect of traffic headaches with the work week set to resume Monday.

“We’re doing everything we can … and we’ll continue to reevaluate our alternate traffic routes,” Stanley said.

The bodies of one man and a child were in the cab of a truck hauling cantaloupe, which appeared to have hit a pillar outside the tunnel, a fire official told The Associated Press on condition his name not be used because he was not authorized to speak about the incident.

The other body was found in a truck about 12 feet short of the tunnel’s exit, said the official.

All the bodies were burned beyond recognition, he said.

County coroner’s investigator Kelly Yagerlener said it could be several days before the names of the dead were released.

Ten victims suffered minor to moderate injuries, and 10 others in the tunnel when the crash occurred managed to escape unharmed, Stanley said.

With so many vehicles trapped inside the tunnel, “there was a potential for a greater number of critical injuries, let alone fatalities,” Tripp said.

The pileup in the southbound truck tunnel began about 11 p.m. Friday. According to early reports, two big rigs collided on the rain-slickened highway.

The tunnel, built in the 1970s, and its mix of curves and darkness has long been regarded by truckers as one of the most dangerous areas of the freeway.

“There’s kind of a blind spot, so if you boogie around the bend too fast and there’s somebody stopped in the tunnel, it’ll be ‘boom-boom-boom,”‘ Arthur Johnson, 45, of Buckeye, Ariz., told the Los Angeles Times.

Truck driver Fausto Angelino said he has been driving that stretch of road for 23 years.

“I hold my breath every time,” he said.

But Failing insisted that the tunnel was safe to use if motorists drove with care.

“I’m aware of no safety concerns,” he said.

Associated Press writer Jacob Adelman contributed to this report from Los Angeles.

AP-ES-10-14-07 1830EDT

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